Understanding Dry Eye

Dry Eye is a common condition experienced by more than 100 million people worldwide. If not monitored and treated, the condition may lead to more serious eye health issues over time. Eye Care Northwest is a TearLab Accredited Dry Eye Center, uniquely experienced in, and equipped with, the most effective dry eye treatments available.

What Causes Dry Eye?

Dry eye occurs when your eye does not produce tears properly, or when your tears are not the proper consistency which causes them to evaporate too quickly.  Often, dry eye can cause the surface of your eye to become inflamed, leading to pain or damage to the cornea, if left untreated.

Your cornea, the dome-shaped outer surface of your eye, is made up of a group of cells and proteins precisely arranged in layers, but it has no blood vessels to nourish or protect it against infection. Instead, it receives nourishment and cushioning from tears on its exterior surface, and a watery fluid (aqueous humor) that fills the chamber behind it.  These systems must be in balance for your eyes to feel comfortable and remain healthy.

Dry eye has increased dramatically as people age, computer usage increases, and environment and medication habits change.  Blinking regularly helps keep the tear film evenly spread across the cornea, and we tend to blink less when viewing computer screens.  Air quality and humidity, and increased medication usage can alter tear film composition.

Those over the age of 50 frequently experience dry eyes, but they can occur at any age. Dry eye is more common after menopause. Women who experience menopause prematurely are more likely to have eye surface damage from dry eye.

Symptoms of Dry Eye

• stinging or burning
• a sandy or gritty feeling,  as if something is in your eye
• excess tearing after a period of very dry eyes
• a stringy discharge
• pain and redness
• episodes of blurred vision
• discomfort wearing contact lenses

Conditions Causing Dry Eye

• Some medications, including antihistamines, nasal decongestants, tranquilizers, certain blood pressure medicines, Parkinson’s medications, birth control pills and anti-depressants can cause dry eye.
• Skin disease on or around the eyelids increases dry eye
• Diseases of the glands in the eyelids, such as meibomian gland dysfunction, increase dry eye
• Hormone replacement therapy may increase dry eye
• Allergies can be associated with dry eye.
• Infrequent blinking, associated with staring at computer or video screens, may lead to dry eye
• Both excessive and insufficient dosages of vitamins can contribute to dry eye
• Homeopathic remedies may have an adverse impact on dry eye
• Long-term contact lens wear can lead to dry eye
• Immune system disorders such as Sjögren’s syndrome, lupus, and rheumatoid arthritis can increase dry eye
• Chronic inflammation of the conjunctiva, from certain eye diseases, infection, exposure to irritants such as chemical fumes and tobacco smoke, or drafts from air conditioning or heating, can cause dry eye
• Thyroid disease which can cause the eye to protrude forward or cosmetic surgery of the eyelids if they are opened too widely, can cause dry eye.
• Eyelids not closing completely during sleep can cause dry eye

Two types of dry eye

Aqueous tear-deficient dry eye is a condition when the lacrimal glands fail to produce enough of the watery component of tears to maintain a healthy eye surface.

Evaporative dry eye results from inflammation of eyelid glands, called the meibomian glands. Meibomium glands create the oily component of your tears, called lipids, which help hold tears together and prevent quick evaporation.  If the tear oil balance is disturbed or malfunctioning, your tears break down at a rate faster than desired, leaving your cornea without the cooling, soothing tear film that keeps eyes comfortable.

Are my tears inadequate?

Tears, made by the lacrimal gland, are necessary for overall eye health and clear vision. Tears bathe the surface of the eye, keeping it moist, and wash away dust and debris. They also help protect the eye from bacteria and infection.

Tears are made up of three layers:

a) the outer, oily, lipid layer is produced by the meibomian glands;

b) the middle, watery, layer is produced by the lacrimal glands; and

c) the inner, mucin layer produced by goblet cells located within a thin transparent layer over the white part of the eye and covering the inner surface of the eyelids.

Tears are constantly produced to bathe, nourish, and protect the eye surface. They are also produced in response to invasive events, such as dust or an eyelash in the eye, an infection or irritation of the eye, or an onset of strong emotions. When the lacrimal glands fail to produce sufficient tears, dry eye can result.

Any disease process that alters the components of tears can make interfere with tear composition and result in dry eye.

Dry Eye Diagnosis

A series of evaluations will be performed to determine what is causing your dry eye.  This will include a LipiView® tear film and gland imaging and a meibomian gland evaluation. Knowing what is causing your dry eye will help Dr. Grayson determine your best treatment option.

Dry Eye Treatment

Based on the outcome of dry eye testing, treatment options exist to correct the condition:

If the issue is tear production, Dr. Grayson will recommend Restasis, a prescription drug which actually increases tear production.

If tear retention is the issue, Dr. Grayson will recommend the insertion of tear saver plugs, called punctual plugs.  These are painlessly inserted, and can be temporary or permanent.

If you’re suffering from chronic dry eye, a condition in which your tears aren’t able to provide adequate moisture for your eyes, Dr. Grayson may recommend Avenova, to help alleviate your symptoms. Avenova functions by clearing debris and microorganisms from eyelids and eyelashes, as well as reducing inflammation, helping to maximize tear effectiveness.

Excessive or Constant Tearing (Epiphoria)

Lubricating tears keep the eye healthy and vision fresh. In some people, tears well up in the eye too often and at inconvenient times because the tears are not draining properly.  Excess tears can spray onto glasses during each blink and can overflow onto the cheek creating a constant mess, sometimes even irritating the skin.

When functioning properly, tears enter a small opening in each eye lid (the punctum) and drain through a small canal (canaliculus) down into the nose. Improper tear drainage and overflow tearing can have several causes, including:

• Malposition of the eyelids or punctum
• Weak or faulty blinking
• Old or recurrent eyelid infections
• Injury to the nose or face

Sometimes, dry eyes can cause tearing as a reflex from an eye desperate for more moisture. A thorough examination is necessary to determine the reason for the excess tearing. If the tear drainage system is blocked, surgery to open or bypass the blockage is necessary. This surgery, known as dacryocystorhinostomy or DCR, restores flow back into the nose from the tear sac, and is performed under general anesthesia.